1. Field of Invention
The present invention relates to a method for providing a side-chain dendrimer vesicle and, more particularly, to a method including two steps of emulsification for causing macromolecular self-assembling of side-chain dendritic random copolymer solution for providing a macromolecular vesicle.
2. Related Prior Art
Macromolecular vesicles have been used to overcome problems related to the un-stability of liposome for some time. An approach to the problems is to use a lipid polymer to form a macromolecular vesicle. Therefore, synthetic molecule templates used for macromolecular vesicles are very important.
In 1990, Discher et al. (B. M. Discher, Y.-Y. Won, D. S. Ege, J. C. -M. Lee, F. S. Bates, D. E. Discher, D. A. Hammer, Science 1999, 284, 1143) disclosed the forming of a macromolecular vesicle via the self-assembling of macromolecules without using templates. The polymeric vesicles derive from diblock copolymer was called “Polymersomes” (polymer-based liposomes). Since then, macromolecular vesicles have gained a lot of attention for two major reasons. At first, macromolecular vesicles are an important issue of intra-molecular interactions and supra-molecular assembling structures. Secondly, the self-assembling structures are cell-mimetic, and exhibit the possibility of responding to other functional groups. Moreover, the macromolecular vesicles exhibit excellent stability, tens or even hundreds of times higher than that of micro-molecular phosphatide (H. Ringsdorf, B. Schlarb, J. Venzmer, Angewandte Chemie International Edition 1988, 27, 113; W. Meier, Chemical Reviews 2000, 29, 295).
In solution, amphiphilic block copolymers self-assemble into various structures such as cylindrical, wedge-like, conical, rod-like and spherical structures have been widely reported. Self-assembly behaviors of macromolecular vesicle are influenced by their chemical structures and processing conditions. Diverse geometric shapes and structures are influenced and controlled by the weight percentages of their hydrophilic soft segments (F. Ahmed, D. E. Discher, Journal of Controlled Release 2004, 96, 37). To prepare the macromolecular vesicles, there are four major methods including direct solution (K. K. Jette, D. Law, E. A. Schmitt, G. S. Kwon, Pharmaceutical Research 2004, 21, 1184), dialysis (V. P. Torchilin, Journal of Controlled Release 2001, 73, 137), emulsification (F. Gao, Z. -G. Su, P. Wang, G.-H. Ma, Langmuir 2009, 25, 3832), and solution-injection (M. E. Yildiz, R. K. Prud'homme, I. Robb, D. H. Adamson, Polymers for Advanced Technologies 2007, 18, 427). A lot of efforts are made on the research of block copolymers that exhibit significant structures and narrow distribution of their molecular weights. It is however difficult to precisely synthesize these block copolymers. In comparison, random copolymers exhibit many chemical functionalities and can readily be obtained. Only a few efforts are however made on the self-assembling of the random copolymers in solution because the random copolymers exhibit unidentified structures and wide ranges of molecular weights.
Self-assembling of amphiphilic random copolymers in aqueous solution to form nanometer macromolecules and to release encapsulated content by external stimulation have therefore gained a lot of attention (F. Tian, Y. Yu, C. Wang, S. Yang, Macromolecules 2008, 41, 3385. ; H.-C. Chiu, Y.-W. Lin, Y.-F. Huang, C.-K. Chuang, C.-S. Chern, Angewandte Chemie International Edition 2008, 47, 1875). Hence, adopting a practicable method to prepare a side-chain dendrimer vesicle to avoid the problems encountered in the prior art is necessary.
The present invention is therefore intended to obviate or at least alleviate the problems encountered in the prior art.